Hotel magnate Leona Helmsley left her Maltese $12 million when she died in 2007. And while it seemed excessive then, the idea has become quite mainstream in 2012.

Attorney Stephanie Rapkin said that establishing trust funds for pets "never was just for Leona Helmsley." She said clients often fund their pet trusts with life insurance or pension payments.

One of Rapkin's clients left money so his cats could not only stay in their home after his death, but it also pays for a caretaker to live in the home.

The trust even went as far as allowing the caretaker to purchase the home at a discount after the cats pass away.

"So she has motivation to keep the cats alive since you're basically living rent-free," Rapkin said. "At the end, she is getting a bonus for being a good caretaker."

Carol Wessels said her dog Jake is more than just her best friend, he's family.

"He's a comfort, a joy," she said. "He's been a companion."

Wessels rescued Jake from a shelter, but she said Jake has done much of the rescuing in her family.

"He helped when I was taking care of my elderly parents," she said. "My son just went to college and I'm an empty-nester, so I'm the luckiest person in the world that I still have him."

Wessels is an estate planning lawyer. She has helped numerous families plan for what happens should they become sick of incapacitated.

She took her own advice and did the same for her dog by creating a trust that will fund Jake's care through family members when she's gone.

"To be honest, these little furry things are money pits," she said. "I don't want somebody who's going to do me the favor of caring for my dog and extend that love to me to be left without any money."

Wessels advised that simply including your pet in your will may not be enough, as it can take weeks or months to get into probate court. She also advised including specific instructions for your pet with the person you choose as your Power of Attorney.

The Wisconsin Humane Society said many pets are surrendered because owners fail to plan for the future of their pets when they're gone. To help educate pet owners, WHS created a free program called Guardians For Life, which helps identify potential new homes for their pets.

"We have a form here that you fill out that gives us all kinds of info about your animal," said Jenny Mueller of the Wisconsin Humane Society. "Their routine, their lifestyle, their favorite toys and treats; We use that information to find them the best home if you were to pass away."